Electromagnetic separation or concentration of minerals



July 31, 1923. 11,463,713

, W. M. MORDEY ELECTROMAGNETIC SEPARATION OR CONCENTRATION OF MINERALS Filed April 2. 1920 2 Sheets-Sheet 1 Jully 3a, 1923. I HALCBFHE I w. M. MORDEY ELECTROMAGNETIC SEPARATION OR CONCENTRATION OF MINERALS Filed April 2, 1920 2 Sheets-Sheet 2 Patented: duly 1923.

an STATES Pars ELECTROMAGNETIC SEPARATION R CONCENTRATION OF MINERALS.

application filed April 2,

To all whom it may concern:

Be it known that I, l/VILLIAM Momus Mon- DEY, a subject of the King of Great Britain and Ireland, residing at the city of Westminster, England, have invented Improvements in or Relating to Electromagnetic Separation or Concentration of Minerals, of

, according to one way of carrying it intopractice, in causing a stream of finely divided mineral material, in the form of pulp, to flow longitudinally through a relatively long and narrow inclined launder or trough, that may be slightly higher at one side than at theother, and is arranged on or over the parallel poles of an alternating current multiphase electro-magnetic system, and subjecting the stream to the action of the multiphase magnetic field set up by the elec tro-magnetic system in such a way that material which is responsive to the action of such a moving magnetic field (and which is hereinafter referred to for brevity and distinction as responsive matter) will become separated from the gangue or other material present which is not responsive to such field (and which is hereinafter referred to for brevity and distinction as inert matter) and be gradually swept by such magnetic field in a lateral direction to the higher longitudinal side of the said narrow launder" whilst the inert matter will be caused by gravity to move gradually in the opposite lateral direction, that is to say,'to the opposite or lower longitudinal side of the launder or trough. In this way, the responsive matter and inert matter, separated more or less completely from each'other, will move simultaneously down the launder and be discharged at the lower end thereof into separate receptacles or be otherwise dealt with. The material instead of being in the form of pulp may, in some cases, be in the dry state. In this case the launder may need to be very steep to cause the material to move along it readily. .The movement of the material may be assisted by imparting a 1920. Serial No. 370,865.

vibrating or jerking motion to the launder, particularly when the material is dry.

From the foregoing description it will be understood that the fundamental feature of the invention is-the use of a long narrow launder, inclined longitudinally, and it may be, transversely, for the passage of the material, which, during its movement down such launder as a whole, is subjected to the action of a multiphase magnetic field emanating from a long narrow multiphase electro-magnet placed immediately under the launder. Such an arrangement may be regarded as a constructional unit. When the material to be treated exceeds the quantity that can be dealt with by such a unit, a number of such units may be used, preferably combined in one structure.

llhe nature and scope of the invention,

based upon the above princi 1e, will be readily understood from the fo lowing description with the aid of the accompanying drawings which illustrate, by way of example and diagrammatically, various ways of carrying the invention into practice. In these drawings, Fig. 1 shows partly in side elevation and partly in vertical section on the line II of Fig. 2, Fig. 2 in plan and Fig. 3 in cross section on the line IIIIII of Fig. 1., one example of apparatus suitable for carrying out the invention as above set forth. The drawings are diagrammatic and it is to be understood that they relate to apparatus that can be used for the treatment of 'pulp or of drymaterial. Fig. 4. shows partly in side elevation and partly in vertical section, a modification. Figs. 5, 6, 7 and 8 are sim1- lar views to Fig. 3, illustrating other modifications of the apparatus. Fig. shows partly in side elevation and partly in vertical section and Figs. 10 and 11 in cross section, further modified constructions of apparatus for carrying out the invention. Fig. 12 is a part plan and'Figs. 13 and 1%: cross sections, illustrating still further modifications.

Referring to Figs. 1, 2, and 3, the mineral material to be treated, hereinafter referred to generally as material, and consisting of a mixture of inert and responsive matters, hereinafter respectively'referred to as a and a in a finely divided condition and usually in the form of pulp, is fed at any su1table rate, as by a feeding device I), from a hopper poles which are made of non-magnetic and nonconducting material. The launders are inclined both in the longitudinal direction and in the transverse direction to any required degree. The material is subjected, during its downward passage through the launders to the action of an alternating current multiphase electro-magnet e constructed of laminated iron and having upwardly projecting or teeth e which are parallel with one another and extend substantially the whole length of the launders. The spaces 6 between the poles or teeth may be either open, as shown, or of the closed type (see Fig. 5) or of the partly closed slotted type (see Fig. 14). The elect-ro-magnet e is suitably magnetized by multiphase exciting windings g, 9 that are preferably disposed longitudinally between the teeth and are connected in any appropriate manner, such that the movement or so called rotation of the field, due to the multiphase currents, will pass as a succession of alternating magnetic waves from one side to the other across the face of the magnet at right angles to its length and to the lengthof the launders. As a consequence, any material in the launders capable of responding to the moving magnetic waves so setup, will, as it moves down the launders d, pass transversely across the launders. The material, as a whole, passes down the launders under the action of gravity, assisted it may be, by any suitable method of agitation, as shaking, jerking or vibrating the launders, or the apparatus as a whole.

By tilting the launders and magnet as described, slightly at right angles to their length, gravitational separating action may I be combined with the electromagnetic action.

For example.'if the moving magnetic field passes from left to right of the launders and if the tilting is such that the left sides of the launders are slightly depressed, as seen in Fig. 3, the inert material a will gravitate towards the lower left hand side of each launder whilst the responsive matter (1. will pass to the right hand side of each launder under the influence of the said field although. such" action necessitates its mov-' lng up a v slightincline from left to right if the launders should be slightly inclined transversely. Thus. during the passage of the, material as a whole down the, launders,

a separation'or concentration will gradually the'matter a leaving the right take place,

1 hand side of each launderri being difi'erent in composition to the matter a H leaving the hand side of each launder. Adjustable three grades of materials will be collectct namely, heads, ,middlings and tailings, any or all of which may, if necessary, be subjected to further concentration by being passed down the launder a second time or oftener, or successively down other launders.

Each launder is made narrow in order that the particles to be separated from the pulp shall have only a small distance to travel transversely,

The strength of the magnetic action can be varied, as for example by varying the excitation, or the distance of the material from the face of the magnet in the successive treatments, or in successive launders. Thus, the more responsive matter may be first separated by a weak electro-magnetic induction, and afterwards, the less susceptible material with a higher induction.

The length of the launder and its slope, both longitudinal and transverse, will be determinedby the nature of the material to be treated. the time necessary for concensponsive portion will, with some materials,

be made more sensitive or responsive to the multiphase field to which it is afterwards subjected, so that the separation and concen tration of the material can be carried out with a lower excitation of the electro-magnet. used for the purpose than would otherwise be the case. For th s purpose, the preliminarv induction may ,for example, be applied by causing the material to pass through the fieldrof one or more electromagnets on arranged in the path of the material on its way to the upper end of the launders d, as shown in Fig. 4. The electromagnet m may be one phase, or multiphase, I

sive matter a to pass completely down the launder, that side of the launder to which it is moved, may be so arranged that such matter will be discharged from it in a lateral direction, the inert matter a passing longitudinally down the trough. This arrangement is shown in Figs. 5 and 6.

The windings g of the electro-magnet e, or their connections, may be so arranged that the magnetic movement of the responsive mattera will be from the middle of a launder laterally in both directions to its opposite sides, so that the inert material a may gravitate to the middle of the launder and pass downwards and escape through a single discharge at the bottom of the launder while the responsive matter a will pass to'the two sides of the launder from which it can be dischargedas indicated in' Fig. 7

; With such an arrangement, the launder and,

it may be, the electro-magnet also, should be slightly curved at right angles to its length, as shown, so that the inert matter a can gravitate to the middle. 01', by providing the sides of the launder with raised edges, so as to prevent the responsive matter a from passing over the sides of the launder, the said responsive matter can be caused to pass down the two side portions of the launder and be discharged at the lower end thereof.

The launder may have over it a laminated magnetic cover d (Fig. 3), or a second magnet c (Fig. 14) may be used having its poles or teeth projecting downwards and facing those of the lower magnet. This may increase the inductive action but does not affect the principle of the invention.

instead of using a separate launder or launders. the material may be caused to flow longitudinally over the surface of the electro-magnet, where the spaces between the poles of the magnet are ofythe closed slot type, as in the example shown in Fig. 5. The surface of the magnet thus forms a launder. Or, alternatively, the electro-mag 'net may be supported with its poles extending downwards, the material being placed on a launder, below the poles, which may be formed by a plain laminated iron structure through which the magnetic circuits are completed, as in the examples shown in Figs.

6, 7 and 8. Or the launder may be of a nonconducting material.

The launder instead of being. inclined, may be horizontal in its longitudinal direction. In either case, the material to be treated may be caused to move as a Whole in either direction along it by the action of asuccession of shocks or jerks imparted to the launder in a manner well known 1n connection with ore dressing machines, the respon sive matter and inert matter passing transversely-to opposite sides of the launder in the manner hereinbefore described. Fig. 1

shows, for. example, a tapping lever 1- arranged to be oscillated by a rota'ry cam s and to impart shocks to the launder (Z.

Although it is advantageous to incline the launder sideways, or to make it concave, in order to cause the inert and responsive portions of the mate-rial respectively to move in opposite directions, the one by gravity and the other under the action of electro- Bil tion. Or, in some cases, the launder may. be

inclined sideways as described and the electro-magnet c be so arranged (see Fig. 13) that the inert matter a will be caused to move laterally and in an upward direction by imparting shocks or jerks to the trough,

whilst the responsive matter a may be prevented from so moving or even be caused to move laterally in the opposite and down- Ward direction by the electro-magnetic induct-ion. In this case magnetic induction.

When treating dry material by the method described, the material may, as shown in Fig. 9. be carried through the multiphase electro-magnetic field by an endless belt n,

gravity assists electrodriven by one or both of the pulleys 0 over which it works, the responsive matter a moving laterally andbeing discharged in any 7 of the ways hereinbefore described. Thus, by using the arrangement ofa magneticfield moving from the middle to each side and by employing a concave belt, the responsive matter a may, as shown in Fig.

10, be discharged over each side of the beltf whilst the inert matter a at the centre of the belt, to which it would gravitate, can be discharged over the pulley at one end.

Or the belt n may, as shown in Fig. 11,

be Hat and be provided with longitudinal flexible ribs or divisions k, for the same purpose as those described with reference t .Figs. 2 and 3, the separate products being discharged over the forward end pulley into suitable places or'receptacles. In this case the belt and magnet will be inclined transversely. If necessary, the belt may, in each case, be shaken or'agitated to facilitate the desired action.

In'lFig. 3 the electric-magnet e is shown diagrammatically as provided-with a winding suitable for two phase or three phase; Figs. 5, 6, 8, 11 and 14.- for three phase; Figs. 7 and 10 indicate a two phase winding, one

phase being applied to the middle pole or I tooth and the other phase to the right and left-hand poles or teeth.

From the foregoing examples it will be iii seen that the principle of the invention can be carried into cll'ect in various ways. It

can be applied in connection with many forms and arrangements oi ore dressing apparatus, such as shaking tables, vanncrs. classifiers and the like, for the purpose of assisting, augmenting or supplementing their actlon.

ing the elcctro-magnetic separation or concentration of tincly divided mineral matter, said method consisting in causing such matter to pass longitudinally over a relatively long and narrow support arranged adjacent to the longitudinal and parallel poles of an alternating current multiphase electro-maguet and subjecting the stream to the action of the multiphase moving magnetic field set up by the said electro-magnet transversely to the said stream and support, the said support being of such length that material that is responsive to the action of such a magnetic field will become separated from the material that is not responsive to such field. and he gradually swept in a lateral direction by such moving magnetic field to one longitudinal side portion of the said support whilst the inert matter will be caused gradually to move in the opposite lateral direction to another longitudinal portion of the said support, the responsive matter and the inert matter being divided iuto'separate streams that'are separately discharged from said support.

2. In the method of separating 01' concentrating mineral matter according to claim 1, supporting the material in a: trans versely inclined plane to permit transverse flgravitational deviation of one of the two portions of matter from the other portion. '3. In the method of separating or con centrating mineral matter according to claim 1, simultaneously agitating the material, substantially as described for the purpose set forth.

4. In the method of separating or concentrating mineral matter according to claim 1, causing the separated responsive matter whilst moving longitudinally to be moved laterally to one longitudinal side of the relatively long and narrow longitudinal support and be discharged laterally over such longitudinal side. v p

5. The herein described method of effecting the 'electro-magnetic separation or concentration of finely divided mineral matter, said method consisting in causing said matter whilst carried by a long and narrow su port to pass longitudinally through and sulljecting it to the action of a multiphase -whilst the inert moving magnetic field moving in a direction transverse to the said support and set up by an alternating current multiphase electromagnet having poles arranged parallel and adjacent to the said support, said support being of such length that material that is responsive to the action of such a magnetic field will become separated from the material that is not responsive to such field, and be gradually swept in a lateral direction by such moving magnetic field to one longitudinal side portion of the said support matter will be caused gradually to move in the opposite lateral direction to another longitudinal portion of the said support, the responsive matter and the inert matter being divided into separate streams that are separately discharged from said support. I

(S. In the method of separating or concentrating mineral matter according. to claim 5, subjecting the-finely divided mineral matter to be treated, to a strong preliminary magnetic induction.

7. For carrying out the method of separating or concentrating mineral matter according to claim 1, apparatus comprising a support in a direction to sweep responsive matter in the mineral matter towards. one of the longitudinal sides of the support.

8. For carrying out the method of separating or concentrating mineral matter according to claim 1, apparatus comprising a' long and narrow launder over which the mineral matter to be treated is caused to move. in the longitudinal direction, said launder having its longitudinal edge portions higher than an intermediate longitudinal portion, and an alternating current multiphaseelectro-magnetic system having parallel poles arranged lengthways of and adjacent to said launder and adapted to set up multiple moving magnetic fields that will travel transversely in opposite directions towards the longitudinal sides of the launder.

9. For carrying out the method of sepa rating or concentrating mineral matter according to claim 1, apparatus comprising a long and narrow launder over which the mineral matter to be treated is caused to move in the longitudinal direction, said launder having a bed of concave shape in cross section and an alternating current multiphase electro-magnetic system having parallel poles arranged lengt-hways of and adjacent to said launder and adapted to set up moving magnetic fields that will travel transversely to said launder and in opposite directions to one another to cause responsive matter separated from inert matter to be discharged over the opposite longitudinal edges of the launder whilst inert matter will be caused to-travel along the lower longitudinal central portion of the launder.

10. For carrying out the method of separ-ating or concentrating mineral matter ac cording to claim 1, apparatus comprising a relatively long and narrow launder, inclined both longitudinally and laterally, and having its lower longitudinal side higher than an intermediate longitudinal portionof said launder and an alternating current multiphase electro-magnetic system having parallel poles arranged lengthw-ays of and adjacent to said launder and adapted to produce a travelling field.

11. For carrying out the method of separating or concentrating mineral matter according to claim 1, apparatus comprising a relatively long and narrow launder, inclined both longitudinally and laterally and having both of its opposite longitudinal sides higher than an intermediate longitudinal portion and an alternating current multiphase electro-magnetic system having parfield and magnetic means adapted toimag netize said mineral matter preparatory to its being subjected to the moving magnetic field of said electro-m-agnetic system.

13. In apparatus for separating and con centrating mineral matter, a long and narrow launder inclined in the direction of its length and in a direction at right angles thereto, feeding means for delivering mineral matter on to one end of said launder, an alternating current multiphase electromagnet arranged with parallel poles lengthways of said launder and adapted to create a travelling field, means for subjecting said mineral matter to a preliminary magnetization before it comes into the moving magnetic field of the said electro-magnet and means for imparting a shaking movement to said launder and mineral matter thereon.

Signed at London, England, this 16th day of'March 1920.

WILLIAMMORRIS MoRnEY. 

